Spark plug



Dec'. 31, 1935. Y A. M. sPRwAY 2,026,143

SPARK PLUG Filed May 8,v 1955 NV ENTOR Patented Dec. 31, 1935 UNITED `STATES Pissiflsla'r` OFFICE SPARK PLUG Arthur M. Spurway, New York, N. Y.

, Appuation May s, 1935, serial No. 20,316

2 Claims. (o1. 12s-169) This invention relates to improvements in spark plugs, and it is the principal object of my invention to provide a neutral member which can be attached to the spark plugs at present on the market without the necessity of making maplug or removed therefrom without any special tools and the use of, mechanical skill.v

Another object of my invention is the provision of a neutral member for spark plugs which is simple and inexpensive in its construction, yet durable and highly eilicient in operation and may 'be sold on the market at a reasonable price.

A further object of my invention is the provision of a neutral member for spark plugs by means of which the spark gap may easily be adjusted.

A.still further object of my invention is the provision of a neutral member for spark plugs consisting of a( three-legged piecey of metal stamped and shaped in/ such a manner that it can be snapped on or screwed onto the insulator .encircling the centerl electrode of the plug so as to produce one spark to jump from the top of thecenter electrode to the bottom part of the top of the neutral electrode, and the other spark to jump from any one of the three legs of thene`utra1 electrode to the side walls of the plug.

It will be evident, that the insulator encircling' the center electrode will have to be threaded in order to receive the threaded part of the neutral electrode, and that the thread on the insu- `/lator will allow the neutral electrode to be screwed Vup or down and thus to adjust the spark gap to the desired distance.

'Ihe fastening of the neutral electrodeto -the insulating member in the aforedescribed manner produces a simplicity of`arrangement'of the elements which enables anyone, even persons not skilled in the art, to readily place the neutral member on the spark plug.

It will be clear thatlwhile I have specified three legs on the neutral electrode, which have proven highly eilicient in practice, and give a pleasing appearance, I do not wish to be remore or less number of legs without departure from the spirit of my invention.

A solid ring is snapped over theneutral electrode after the same has been properly adjusted on the spark plug and will hold the electrode snugly and properly in place on the porcelain insulator.

While no changes need to be made on `the usual type of spark plugs, with the use of metric type plugs it may be necessary to cut away a l0 Vsmall amount of metal inside at the ring end of the plug to make room for the neutral electrode.

These and other objects andadvantages of my invention will become more fully known as the 15 description thereof proceeds, and will then be specifically dened in the appended claims.

In the accompanying drawing forming a material part of this disclosure:

Fig. 1 is a front elevation of a neutral electrode for spark plugs constructed according to my invention.

Fig. 2 is a top plan view thereofon a spark plug.v

Fig. 3 is a fragmentary longitudinal section through a spark plug equipped with a neutral electrode constructed according to my invention and screwed onto the insulating central plug member.

Fig. 4 is a view similar to Figure 3 illustrating the neutral electrode as being snapped onto the insulating central member. Fig. 5 is a section on line 5 5 of Figure 4.

Fig. 6 is a detail view of a modied form of neutral member.

As illustrated, a spark plug I0 of any well known type'and construction equipped with the central insulator II has the `upper end of this insulator threaded, as at I2, and located in the cut-away portionf I3 of the plug at the firing end. A neutral electrode I4 or member having three or more or less legs l5 spaced from one another has the inner faces of these legs threaded as at II6, to fit the threaded upper end of the .insulator member, as shown in Figure 3.

The upper part of the neutral member has formed in its outer face an annular groove I1 for l y stricted to the use of three legs, as I may use a trated in Figure 6 the legs I9 have varying width `55 of the electrode.

It will be clear, that the neutral member will cover the central electrode so asto prevent oil to splash on the same, and that the said member will get hot so quickly as to immediately vaporize any gasoline which may be spilled in starting the engine.

A In use, the neutral electrode will be placed onto the insulator of the central electrode and will be held thereon either by screwing it to the top of the insulator, or by snapping it over the same and holding it in place by means of the split ring, so as to protect the central electrode against oil and gasoline, and to provide a gap for the spark to jump from the top of the central electrode, particularly its thickened part to the bottom part of the top of the neutral electrode, and Ialso a spark to jump from any of the legs of the neutral electrode to the side walls of the spark plug. Thus, I have produced a neutral electrode or member which will prevent a too 5 rapid accumulation of carbon and which can be snapped on any spark plug Without materially changing the same, and which may be replaced at a minimum of cost, thereby considerably lengthening the life of the spark plug. 10

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a spark plug, a neutral electrode and an insulator therefor comprising a multi-legged body l5 provided with an annular groove on its outer circumference, and a ring in said groove for holding the neutral electrode in place on'the insulator for the central electrode of the spark plug.

2. As an article of manufacture, a neutral 20 electrode for spark plugs comprising a body part having a groove formed in its outer circumference, and legs suspended from said body and spaced from one another, and a split ring in said groove to hold said neutral electrode in position 25 on the spark plug.

ARTHUR M. SPURWAY. 

